textproduct: Quad Cities

KEY MESSAGES

- Showers and storms will develop mid to late evening and overnight. An isolated severe storm is possible west of the Mississippi.

- There is an Enhanced (level 3 out of 5) risk for severe storms Monday into Monday evening. All modes of severe weather are possible.

- Turing cooler Tuesday through Friday with a slight warm-up for the weekend.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 223 PM CDT Sun Apr 26 2026

Quiet, dry and seasonable conditions will be seen into the early evening hours. Attention then turns to the late evening and overnight.

Starting mid to late evening, the LLJ will veer into eastern Iowa. When this occurs elevated convection north of the warm front will begin to move into eastern Iowa.

The very short term models appear to be converging toward a round of showers and thunderstorms roughly from 9 PM to 3 AM with the better coverage south of I-80. Areas south of I-80 and west of the Mississippi may see an isolated severe storm with hail the primary risk.

There may or may not be a brief break before round 2 develops along the northward moving warm front around sunrise. This round would also be capable of a few severe storms with wind/hail being the primary risks but brief spin up tornadoes cannot be ruled out.

The question is how long does round 2 last? Here the very short term models diverge on their solutions. Some say through mid-morning while others suggest mid-day. Regardless of the solution, the overall synoptic picture depicts a LLJ of 50 knots pushing moisture into the area with diffluence aloft producing synoptic scale lift. These features combined with outflow boundaries from the morning convection will provide numerous foci for diurnal convection to develop in the afternoon.

As mentioned yesterday, two scenarios are in play with a 50/50 chance of either occurring;

1) Convection persists into the afternoon which limits diurnal heating. Net result is persistent storms across the area. The severe risk would still remain but the primary risks would be damaging winds and brief spin-up tornadoes with hail a secondary risk.

2) The morning convection dissipates quickly allowing strong diurnal heating. The net result is more widespread strong to severe storms. The initial discrete storms would be capable of all severe modes (including stronger tornadoes). Once the storms grow upscale into lines, damaging winds and brief spin-up tornadoes become the primary risks.

Areal coverage of storms should reach a maximum in the 4 to 7 PM time frame. After 7 PM, the advancing cold front will push all storm activity east of the area by 9-10 PM.

Mainly dry, breezy and cooler conditions will be seen across the area after midnight.

LONG TERM /TUESDAY THROUGH SATURDAY/

Issued at 223 PM CDT Sun Apr 26 2026

Tuesday through Sunday Assessment...a certainty (>95%) of cooler temperatures through Friday with a small warm-up for the weekend

Northwest flow will develop across the CONUS resulting in cooler temperatures for the remainder of the week. A small warm-up is in store for the weekend.

Much of the time period will be dry. However, there are a series of weak disturbances aloft that will move through on a near daily basis that could produce some isolated showers or even a rogue thunderstorm.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1231 PM CDT Sun Apr 26 2026

Winds will occasionally gust up to 20 knots through sunset with VFR conditions. After 03z/27 elevated SHRA/TSRA will begin moving into southeast Iowa as winds aloft bring moisture into the area. Convection will be isolated to scattered with the better coverage south of Interstate 80, especially toward sunrise Monday. Marginal LLWS will develop prior to sunrise along/east of the Mississippi that will last through 14z/27. There may or may not be a break before the diurnal convection develops across eastern Iowa prior to 18z/27.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.